Grade 11Analytical Geometry

A ray of light coming from the point (1,2) is reflected at a point A on the y-axis and then passes through the point (5,3). What are the co-ordinates of point A?

Bhore

9 Years agoGrade 11

2 Answers

Vijay Mukati

9 Years ago

Dear Student

Here you should take three cases
Case (1) Point is at origin,
Case (2) Point is above origin (0,y) , y>0
Case (3) Point is below origin (0,y), y<0

And for all the three cases find the slopes w.r.t point A, and use the concept that incident angles = reflected angle and find the possible values of y, you will get your Points A.
(Origin will not satisfy the concept)

Thanks, Vijay

Bhasker Goel

Approved Tutor Answer9 Years ago

Find the reflection of point (1,2) w.r.t y-axis. By simple geometry you will find that point of reflection of (1,2) i.e. (-1,2) , point A and (5,3) are collinear. So you can easily find the coordinates of point A by finding the equation of the line using the other two co-ordinates.